Depositional properties and geochemistry of Holocene perched springline tufa deposits and associated spring waters: a case study from the Denizli Province, Western Turkey - Tufas and Speleothems: Unravelling the Microbial and Physical Controls - page 244

Fig. 3. Field view of the active waterfall and lobe-top terrace areas developed in front of Sp-4. The flat lobe-top terrace
is presently used as an agricultural area by local people. The water of Sp-4 flowing through an elevated channel
(dotted sinuous line) on the terrace area reaches to the spill-over point of the active waterfall-top. A primary cave (P.C.,
arrowed) has developed within the active waterfall tufa body.

with a HACH Sension 5 conductivity meter. CO 2
and HCO 3 were determined volumetrically by titra-
tion using NaOH and H 2 SO 4 , respectively. Water
samples were collected for chemical analysis and
each water sample consists of two 500 ml poly-
ethylene bottles. One of the bottles was acidified
with ultra pure HNO 3 (pH , 2) after filtering with
0.45 mm cellulose membrane filters for the determi-
nation of cations and the other was unacidified for
anion

samples were determined using a UNICAM
atomic absorption spectrometer. Cl and SO 4 were
determined by a HACH DR/4000 visible spectro-
photometer. The stable isotope (d 2 H, d 18 O and
d 13 C in DIC of water) and d 3 H analyses of some
waters were performed at the laboratory of the
Faculty of Earth and Life Science in Vrije Univer-
sity (Amsterdam) and at the Geological Engineer-
ing Department in Hacettepe University (Ankara),
respectively. Mineral saturation indices of hydro-
thermal minerals were calculated using the
PHREEQC computer code (Parkhurst & Appelo
1999).
The tufa samples were examined by optical
microscope in thin section and some selected
samples were studied on a scanning electron micro-
scope (SEM; Jeol JSM 6490 LV). SEM investi-
gations were performed at Turkish Petroleum
Corporation (TPAO) in Ankara. The mineralogy of
the tufa samples was determined by X-ray diffrac-
tion (XRD) using a Phillips PW 1729 diffracto-
meter at the Geological Engineering Department,
Hacettepe University. Major and trace elements

analyses which is kept at a temperature

equal to lower than þ4 8C.
Both active and passive tufa samples were
collected for mineralogical, petrographical and
geochemical analysis (including major and trace
elements, SEM investigations and isotope

composition).

Laboratory work

Major constituents of water were determined at
the geochemistry laboratory of the Geological
Engineering Department at Pamukkale University.
Ca, Mg, Na and K concentrations of the water